We need fuel cells because they will provide electric power in applications that are currently energy-limited. What is the most annoying thing about your laptop computer? If you answered, “the battery gives out after a couple of hours,” you know why we need fuel cells. Fuel cells are also environmentally clean, meaning that they are ideal for backup power units in buildings where the alternative (a diesel generator or a bank of lead-acid batteries) is environmentally unacceptable. Fuel cells will enable a new range of power uses in small electric two-wheeled and four-wheeled vehicles and in buildings that are remote from the power grid. In the longer term fuel cells will penetrate the huge automotive market, because they offer increased fuel efficiency and are environmentally cleaner than the internal combustion engine